1. Field of the Invention
The present invention relates to a connector device including a plug and a socket, and particularly to a lock structure for locking together the plug and the socket.
2. Description of the Related Art
A card edge connector includes a combination of a plug including a plurality plug pins (plug terminals) and a socket including a plurality of socket pins (socket terminals). The plug is provided at an edge portion of a card member such as a printed circuit board. The socket pins are connected to an external circuit. The plug terminals of the card member are configured as pad electrodes. The socket terminals are configured as contact electrodes which contact surfaces of the pad electrodes when the plug of the card member is inserted into the socket. In a card edge connector, the pad electrodes are constructed as parts of printed wires of the card member. The card edge connector has a shorter wiring length, compared with a two-piece connector in which a plug is provided separately from the circuit body. Therefore, the card edge connector has an advantageous feature of capability of reducing electric loss under the condition of using high-speed signals.
Sockets for the card edge connector are divided into several types, e.g., a type of socket which is provided at an edge portion of a printed circuit board like a plug, and another type of socket which is connected to an end portion of a cable. Particularly, the latter type has a problem in that the card member easily falls off when the cable connected to the socket is pulled by an external force. Patent Publication JP-2002-124327A (FIG. 1) and Utility Model Publication JM-61-76683A (FIG. 1) describe a card edge connector having a lock structure between a card member and a socket, as a kind of card edge connector which prevents the card member from falling off from the socket. In the lock structure described in JP-2002-124327A, the card member is provided with a hook-like protrusion and the socket is provided with a pivotable lever. When the card member is inserted into the socket, the lever is shut to engage with the protrusion. In the lock structure described in JM-61-76683A, through-holes are formed outside the area in which a plurality of pad electrodes are arranged in the card member, and protrusions which engage with the through-holes are provided in the socket for locking the body of the plug and the body of the socket.